1. Field of the Invention
The invention relates to a keypad and its operation method, and in particular to a keyboard having several input keys and several sets of key-signal tables of the corresponding key signals, so that when a input key is pressed, the corresponding key signal is obtained from one of the corresponding key-signal tables, and is transmitted to the digital device to execute the specific action or for display required.
2. Related Art
In consideration of compactness and miniaturization, the separate set of numeric keys on the right side of the ordinary desk top keyboard is omitted for the notebook computers, and only the composite key set composed of the keys of all the numbers and a part of the characters remains. However, such a composite key set replacing the purely numeric keys is not quite convenient. Therefore, most of the users attach an additional numeric keypad to facilitate the input of numbers. For the computer users required to do a large amount of numeric input, the numeric keypad is indispensable. However, numerous problems frequently arise in the actual application of the numeric keyboard. This phenomenon is particularly evident when it is utilized in cooperation with the notebook computer.
Usually, when an additionally attached numeric keypad is used for numeric input, it is effective only when the Num Lock modes of the computer and the numeric keypad are ON. However, when the Num Lock function of the additionally attached numeric keypad is activated, the Num Lock function of the computer keyboard is also activated synchronously, which results in the consequences that when the keypad is used to input numbers, the characters of the composite key set can not be input, thus making the numeric keypad less convenient.
Presently, the solution to this problem is to provide driving software in the computer system for the additionally attached numeric keypad. When it is desired to input numbers through the numeric keypad, the driving software is used to activate the Num Lock function so that when the key is pressed it is in the ON state, and upon receiving and executing the corresponding key signal, the Num Lock function is deactivated immediately, so that the Num Lock function is in the OFF state. However, the application of this method involves the complicated installation process of the driving software, and it must also ensure that the driving software is compatible with the original system software in the computer. Furthermore, sometimes the original driving software may be replaced by the additionally installed system software. As such, the application of the method is restricted by the driving software and other program software.
Alternatively, another solution to this problem is to change the contents of the packets transmitted, so that on receiving the packet, the computer enters into the ON state of the numeric lock (Num Lock) function, thus executing the key signal corresponding to the numeric key pressed. In this respect, one of the methods utilized is to switch the computer to the ON state of the Num Lock function for executing the corresponding key signal by making use of the packets containing the Num Lock key signals before and after the transmitted key signal. Another method utilized is to send out a deceiving packet before sending out the packet of the corresponding key signal, so that the computer is in the ON state of the Num Lock function to execute the corresponding key signal. However, in the application of these methods, the computer must first enter into the ON state of the Num Lock function, so as to execute the key signal corresponding to the numeric key pressed. As such, it tends to cause mutual interference between the numeric keypad and the computer and confuse the user.
Though numerous solutions have been proposed to solve the problem created by the synchronism of the numeric locking functions between the numeric keypad and the computer keyboard of the prior art, yet they have met various problems in actual implementation, thus there is still much room for improvement.